8th Grade Force

Which of the laws of motion states, “To every action there is an equal but opposite reaction”?

• Newton’s 1st Law

• Newton’s 2nd Law

• Newton’s 3rd Law

• Law of Conservation of Momentum

Which of the following factors does not affect air resistance?

• Speed

• Spin

• Size

• Shape

Momentum describes

• How much force is needed to change an object’s motion

• How much velocity changes in a given amount of time

• The tendency of an object to resist a change in motion

• The balanced forces on a falling object with a constant speed

Which of the following items has the most inertia?

• A pencil

• A textbook

• A water bottle

• The teacher

Carl and Juan are playing catch.  Carl throws a fastball to Juan and it hurts Juan’s hand.  Why is this the case?

         

• Greater the acceleration, greater the force   

• Greater the mass, greater the acceleration

• Greater the acceleration, the less the force

• Greater the acceleration, the less the force

A person is on a paddleboard. The person exerts a force on the water with the paddle, causing the water to move. The paddleboard also moves, but in the opposite direction. Which statement best explains why this happens?

        

• Inertia

• Action and reaction forces 

• Newton’s 2^nd Law of motion

• Law of Conservation of Momentum

.  Consider a watermelon that starts from rest and drops straight down from a tall building. Air resistance can be ignored. Which statement about the watermelon’s motion is FALSE?

• The watermelon falls at a constant velocity.  

• The watermelon has a positive acceleration. 

• The watermelon’s acceleration due to gravity is 9.8 m/s².

• The watermelon speeds up as it falls

What is the weight (in Newtons) of a person with a mass of 95 kg?

• 9.7 N

• 95 N

• 104.8 N

• 931 N

. An object has 16 N of force being applied to the right, 16 N of force being applied to the left, and 4 N of force being applied downward.  What is the net force on the object?

• 36 N

• 4 N downward

• 32 N

• 16 N to the left

A 700 kg car is driving with an acceleration of 5 m/s² down the interstate.  What is the force required to accelerate the car?

A.  3,500 N                              C.  14 N

B.  650 N                                  D.  0.071 N

• 3,500 N

• 650 N

• 14 N

• 0.071 N